Pressure unit for intaglio printing



Oct- 13, 1931- A. T. CHESTER ET AL 1,827,685

PRESSURE UNIT FOR INTAGLIO PRINTING Filed Oct. 9, 1929 INVENTOR ART/fw? .0H TER A. cxr CARY M? MM ATTORNEY@ l Patented 13,1931 l A L i 't UNITED STATES PATENT OFFICE i Anma'ncnrsmmacmxroncaiimor BYE, NEwYonx PBESSUBEUNIT FOB INTGLIO PRINTING Application led October 9, 1929. Serial lo. 398%9.

This invention relates to the art of intaglio A further object, therefore, of the present printing and its object is to improve the Invention is to provide a pressure vunit for pressure-applying unit in devices used for Prlnting from an intaglio plate, or from a this purpose, plurality of such plates, wherein the same v l By reason of the way in which intaglio moyement of the piston or bed, of the press, 55

plates are made the surface of such a plate. Which brings the plate and pressure unit toi is not a true plane, even in those parts whore gether also causes printing. This we accomno engraved lines occur. Some of the enp lisb by introducing between the substangraved pari-,s as a whole are in a Slightly dif. tially iniiexible base of the pressurev head, 1 `,ferent plane from other parts considered as $11@ th? P18118, a I'Iledlllm which iS leXble and oo o whole, and, in addition, there are slight, irlwhich 1s so confined that it will distribute the regulan-ities of Surface which are the result pressure to d iierent portions of the surface ofthe hardening process to which these plates 0f @h e plate ll'leSPeCtlVe 0f its major irreguare subjected.l These general irregularities lfilltlesv of surface are referred to in the following Theorptlcally, and, as we have found. praco5 description and claims as"ma]'or irregularitlcally, it takes .less pressure to distort the ties. In addition to these are the depres- RRPQT'IDO the Wlde 111195 0f the engraved P01" sions ofthe lengq-,We 1 lines into which the tions of the plate than into the narrow lines. paper to be print-,ed moet be forced by the The added 'pressure necessary to p roduce perpressurapplying .means of the press In fect imprcssionspf the narrow lines creates 70 preparing a platefor printing, according to what, for convenience we term an mk pres-- well known practice, various methods of 'Sure H1 th? Wlde llllS- ThlS Pressure make ready have been employed to take squeezes the ink out of the lines against the care ofwhat might be the major irregularilockmg Pressure 0f 11h@ Papel at lh@ edges 0f 35 ties i 1 y these lines, thus causing af eather1ng or blu1'.4 75

The present inventionis also an improve rmi;r of the wide hnes which destroys their ment on the device disclosed in our applicasharpnesstion Serial No. 385.504. filed August 13, 1929, Ths.fault.is pllesept in the ordinary meth' i and in said application we disclose an M ods of intaglio printing and heretofore it has rangement of printing unit whereby the bteen tqicult if not impossible to eliminate 8 make .read-v. mgthods heretofore.employed l fili tllli drdnary process of printing a steel ssissffziaaiseeWW' im in im fue mehr' I nis est epressure ort eprintmg.l oritalglgldglllcatg; ell lgeioarl der. however, thatthe paper may be squeezed 85 uuid p P re gamers are ran ed in a into the various hnes forming vthe engraved printing head Each .of these fluid gpressure portln of the pltat 1t htas ndfoutneg ntoesaryonseamarixmaeriaaap e iig-cms Para? 3:11am? www 3911;; inmaterial mi In theparticnllr disclosure of the application intuthlllxlgage 151g; byxhelgggteam 9 the exible Wall Consists 0f a bag 0f rubber the roller,-at all points of the plate and it or other suitable flexible material into which is this necessary qualify of the matrix mate. fluid Pressure iS Supplied'aftel' *Piston u D rial that causes the feathering or blurring u which the plate to be printed iS SUPPO is above referred to. 96 ltioulfltt 1p lontlttawlgh thvmetl Por- We fim found that totome extent the n e P re C0 elsame eat ering' exists' in ressu 't AQ Qbiect 0f the .Present qvelltioll S the forming the subject matter gfpour arpiplIi-.- w Egovlsion of means for producing very sharp y tion abovereferred to, we use a preses over the entire prmted Surfm sure container of rubber or similar substance ion which'likewise, in conforming to the engraved lines, produces feathering where such linesl are wide.

In the present invention this feathering is entirely overcome and sharp lines produced by the provision of a material interposed between the pressure head and the matrix material commonly used, the interposed material having such flexibility that it will read# ily conform to the major irregularities 'of the plate and therefore transmit the pressure applied thereto. Said material, however, is not suiciently flexible to readily conform to the engraved portions of the plate. The matrix material lis relied upon to enter these engraved portions. Furthermore, we bacli up 'this liexble material with a flexible medium interposed between the substantially inflexible surface of the pressure unit, and the material, such medium having such flexibility that it will distribute the pressure over the surface of the plate.

This medium may be a fluid such as water, introduced into a pressure container or permanently confined, to produce the printing impression after the plate and printing head are brought together; or such medium may be a solid of the proper degree of flexibility and also confined so that the movement vto contact the plate with the medium and the print'- ing impression takes place as a part of the movement.

While the invention is particularly applicable to the type of pressure head disclosed 1n said application we do not intend that our claims shall 'be limited to its use with any 4particular kind of pressure head or pressure unit.

' Various other importantv features of the invention will become apparent from the following more detailed description with reference to the accompanying drawings, in which Y Figure 1 is an elevation more'or'less diatainer, andillustrating the blurring or feathering effect referred to Figure 3vis a similar sectional view showing how the feather'ing is overcome by the present invention;

Figure 4 is a perspective view ofthe parts 'shown in Figure 3, but on a smaller scale and' more complete; v -f Figure 5 showsva confined, flexible medium'. l which may be used instead vof the pressure container of Figures 2l or4 3; and

Figure 6 is another form which said `conlined, flexible medium' may take. 'y Referring to the drawings, and more par ticularly to Figure 1, there is shown a piston 5 which is similar to the piston having a like reference character in ou'r application immediately above this is shown a pressure container 6. In order to appreciate the advantages of the present invention it will be .necessary to describe in a general way the mode of operation of the printing head disclosed in our prior application above referred to. In said device, printing pressure is applied to the plates through the medium of fluid pressure containers.- Each of these containers consists of a metal plate recessed on its lower face and cemented on the recess is a bag of rubber or other flexible material having the corners reinforced by leather. The flexible container or bag is shown at 16, Figure 2, and fluid, such, for instance, as water, may be introduced into the container through a connection 18 tapped into one side of the container as shown at 19, Figure 1. The pressure head or cap of the press is properly connected with a base to sustain the necessary pressure.

The construction is such as to produce a greater pressure tending to hold the various plate holders and containers against the head ,4 than is applied within the containers thempressure.. This is subsequently applied by introducing fluid pressure into the containers. In the present invention weprovide a type of flexible medium through which the prmting is done by the direct pressure of the piston.

Reverting now to thelirst object of the invention and referring to Figure 2,Y the engraved depressions in the plate 13 are shown at 50,51 and 52. These are shown somewhat exaggerated as to size in order to illustrate the feathering action to which reference has already been made in the opening .para aphs of this specification. .Each of these epressions lis filledwith' ink priorto the positioning of the plate within the printing head, and due to the` ready flexibility of the wall of the container 6 thereis a greater distortion of its lower portionsinto the widerengraved portions than in the narrower ones. depression 50, for instance, the container is 'distorteda considerable distance. It is distortedless in the depression 52`and very little in the depression 51. When the flexible con- Vtai'ner is distorted into the wider depressions or feathering -of the lines'- and the finished print is not entirely sharp.

In theand pressure head. As here illustrated, it

is not necessary to use the flexible bag 16, al-

though this may be used. It is suflicient to have the base plate 6 recessed and fluid is supplied to the recess through the conduit 18 as in the device shown in Figure 2, which is similar to that described in our application.

The lower face of the recess is covered by awall 53 of material which may be of metal or other suitable substance.

In the form of device shown in Figure 3 water or other substantially incompressible Huid is the medium through which pressure applied to the base 6 is transmitted to the wall, and since the fluid is substantially incompressible and flexible it distributes the pressure applied to it.

The wall substance, therefore, must be sufficiently flexible to accurately transmit this pressure and conform to the major irregularities of the surface of the printing plate. It must not, however, be so flexible as to readily conform to the engraved portions of the plate. Any substance having the degree of flexibility within'these limits may be used. l

In order that the paper may be forced into the engraved portions of the plate, a matrix material 54, such as is commonly used for this purpose, is interposed between the wall substance and the plate.

By the construction above described, printing pressure is distributed over the surface of the plate and the'reltivelv higher portions thereof are not subjected to materially greater pressure than the lower portions. With such a construction, therefore, the impression is very sharp and the feathering or blurring Y ofthe wider lines does not occur.

Y In Figure 5 we have shown a confined flexible medium and in Figure 6 another form which this medium may take.

, In Figure 5 the base 6 is recessed as in the v metal and preferably a face plate 64 is provided to prevent the bag from sagging. The

previously described form, and the flexible medium, which in this form is illustrated as va fluid 60, is confined within a fluid container 61. This container may consist of a rubber bag having its edge 62 reinforced with leather or other suitable material. It is also confined around its lower edge by a frame 63 of lower portion of the fluid container extends somewhat below the surface of the-base plate 6 and suicient fluid is originally introduced into the bag to completely fill it, and the bag is then permanently sealed. As the piston rises and the surface of the plate. with an interposed layer of matrix material, contacts with the wall 64, there may be a very slight very small.

compression of the fluid container due to slight elasticity of its walls and to the elasticity of the leather or other reinforcement. This compression, however, is very slight and the parts are so proportioned that when the piston has taken up'this compression, the gap between the piston and the wall 64 is Since the confined fluid is substantially incompressible the slightest further movement of the piston will apply printing pressure. y

This form of device maybe preferable to that shown in Figure 3, because it insures somewhat faster operation of the press.

It will be remembered that the Figure 3 construction follows the method described in our application above referred to', in which the piston and all of the containers 6 are moved into contact prior to the introduction of the fluid within the containers. This is necessary to prevent a blow-out and the timing must besuch as to insure the pressure being introduced within the containers subsequent to the closing of the parts. With the construction of Figure 5, therefore, a simpler mechanism may be used.

Figure 6 shows another form which the confined flexible medium may take. vThis figure is quite similar to Figure 4 and there is placed within the recess of the plate 6 a flexible medium which is a solid having the desired flexibility, and a substance suitable for this purpose is substantiallypure rubber. Rubber of this character is substantially incompressible and it may be made sufliciently flexible to equalize the pressure in different parts of the plate due to surface irregularities. greater than is necessary todo this and therefore in using such a medium' it would be nec-V essary to interpose a matrix material of sufficient flexibility to conform to the engraved portions of the plate.

The solid material, whether rubber or other ,substances having the required properties, may, however, have a flexibility suficient to conform to the engraved portions of the plate and in this event, to get a sharp impression in printing, it would be necessary to interpose between the medium and the' ,material 54 similar to that described in connection with Figure 3 is interposed between the medium 70 and the paper' which is indicated at 55, the plate being indicated at 13. In

The flexibility, however, need not be this form of device, also, the same movement of the piston which brings the various elements together likewise produces the printsubstance, may be used with the flexible containers described in our co-pending application above referred' to, and is not limited to the form of the invention shown in Figure 3. As illustrated in Figure 2 and in Fi re 3 the flexible medium is confined only uring the actual printing and is not permanently confined as in the vforms of the invention illustrated in Figures 5 and 6.

It is also to be notedthat the material 53 need not necessarily be aseparate and distinct unit from the bag or container 61 as illustrated in Figure 5, or the solid medium 7() as Vshownin Figure 6; Such wall may be a surface integral with the container 61 or the medium 70, but suiciently inflexible so that it will not readily conform to the engraved portions of the plate.

Other variations not specifically enumerv ated may be resorted to within the scope of the invention and without departing from the spirit thereof.

W at is claimed as new is:

1. A pressure unit for printing from an intaglio plate, said unit including a substantially infiexible base, a confined flexible medium adjacent the pressure face of the base,

Vand a material overlying said flexible medium and through which the printing pressure is applied to the plate, said medium l' f having such flexibility that it will distribute the pressure over thev surface of the plate and said material having such flexibility that it will transmit the pressure to the plate as determinedby the distortion of the medium and conform to the surface variations of the plate, but net` sufficiently flexible to readily conform to the engraved portions thereof.

2. A pressure unit for. printing from an l intaglio plate, said unit including a substand tially inflexible base recessed for a portion of its area, a wall overlying said recessed area of material sufficiently flexible to readily conform to the major irregularities of the plate but not sufficiently iexible Ato readily conform to the engraved portions thereof, and a constant volume flexible medium Within the recess.

3. A pressure unit for printing from an lying said recess, a constant volume iexible medium within the recess, and amatrix material adjacent tlie wall adapted to Contact with the material to be printed.

A 5. A pressure unit for printing from an intaglio late, said unit including a substantially in exible base, a flexible medium adjacent the pressure face of the base, and a material overlying said fiexible medium and through which the printing pressure is applied to the plate, said medium having such flexibility that it will distribute the pressure over the surface of the plate and said material having such iiexibility that it will transmit the pressure to the plate as determined by the distortion of the medium and conform to the surface variations of the plate, but notsuciently iiexible to readily conform to the engraved portions thereof.

6. A pressure unit for printing from an intaglio late, said unitincluding a substantially in exible base, a confined flexible medium adjacent the pressure face of the base and a material separate from the confining- -means overlying said iexible medium and dium and conform to the surface variations of theplate but not sufficiently flexible to conform to the engraved portions thereof.

7. A pressure unit for printing from an intaglio plate, said unit including a substantially inflexible base, a confined flexible medium adjacent the pressure face of the base and a material adapted to be inserted between the flexible medium andthe plate, said medium having such flexibility that it Will distribute the pressure over the surface of the plate and said material having such iexibility that it will transmit the pressure to the plate as determined by vthe distortion of the medium and conform to the surface variations of the .plate but not sufficiently flexible to conform to the engraved portions thereof.

. signed at New York, N. Y., this sah aay intaglio plate, said unit including a substantially iniexible recessed base, a Wall' overlying said recess and a constant volume flexible medium w-ithin the recess, and through which medium and wall printing pressure is applied to the plate.

4. iA pressure unit for printing from 'an intaglio plate, said unit including a substantiallyinflexible recessed base,- a wall over: 

